In wireless data systems such as cellular broadband smart phones and other devices, the desire for maximum connection speeds is balanced by transmission constraints such as a desire to avoid adjacent channel interference, a desire to avoid transmission modem saturation that can occur above certain power levels, and other transmission conditions or criteria. Under wireless industry standards used to guide power transmission levels, different maximum power reduction (MPR) levels are specified for different channel conditions or configurations. The High Speed Uplink Packet Access (HSUPA) Category 7, 3GPP Release 7 standard, for instance, specifies or requires that packet uplink systems using a single carrier provide a finite number of possible MPR values, depending on channel configuration or operating conditions. The total number of possible power reduction levels can be stored in less than one megabyte of memory using indexing, compression, and other techniques. This represents a manageable amount of memory that can be implemented today on many smart phones or other devices. Data rates of 11.5 Mbits/sec are possible in HSUPA-7 systems.
However, the wireless industry standards which regulate wireless data technology continue to evolve. In the forthcoming High Speed Packet Access (HSUPA) Category 9, 3GPP Release standard, for example, wireless broadband devices will evolve to include modems or other transmission hardware which utilize not one, but two carriers, in part to create the possibility of increased uplink data rates. Data rates of up to 23.0 Mbits/sec are in fact possible under HSUPA-9 devices, permitting broadband users and content providers to enjoy enhanced data delivery. However, with the incorporation of not one but two carriers in HSUPA-9 systems, the determination of the MPR values over various channel configurations and conditions becomes considerably more complicated.
In actuality, since two carriers are used, each having independent and potentially continuously variable power levels, the number of possible MPR values becomes unlimited. Possible approaches for the reduction of that unbounded number of MPR values can be considered, including, for instance, the quantization of permissible reduction values on each carrier over selected incremental ranges. However, even using a quantization type of approach, the number of possible combinations of carrier power levels across the two carriers remains unmanageably large. Reducing or limiting the number of permissible carrier power levels to twenty-one, for instance, still results in a total number of combined carrier power levels on the order of a billion combinations. The storage of that number of discrete MPR levels would be impossible or impractical on today's smart phones or other wireless data devices.
It may be desirable to provide methods and systems for memory-efficient storage and extraction of maximum power reduction (MPR) values in two-carrier wireless data systems, in which the entire range of MPR power reduction levels can be encoded and stored in a relatively compact memory footprint on a mobile data device, allowing valid MPR values to be extracted or generated in real-time operating conditions for HSUPA-9 or other two-carrier platforms.